EPON中ONU软件升级技术的研究与设计

分析了EPON系统中OLT对其下属的所有在线ONU实现软件升级的技术,以及升级过程中OLT与ONU进行OAM消息交互的流程,并在此基础上提出了ONU侧软件升级的具体设计方案.OLT能通过TFTP协议完成文件的传输,统一管理和维护ONU的升级状态,使ONU在升级出错的情况下能实现自动回滚.     

GPON系统中OMCI管理方案设计(本期优秀论文)

OMCI协议是GPON系统中实现OLT对ONU控制管理的标准协议,实现OMCI协议的管理方案设计成为一个核心问题.本文介绍了OMCI协议功能,根据模块化设计思想,对OLT和ONU中的OMCI功能模块进行设计,最后在OMCI模块设计的基础上,给出OMCI消息在OLT和ONU各模块之间的处理流程.     

RIP协议在GPONOLT上的实现

为适应网络扁平化发展趋势的需求,运营商明确提出吉比特无缘光网络(GPON)光线路终端(OLT)要向汇聚型OLT发展,使其同时具有汇聚交换机和边缘设备的接入功能.针对此需求,对GPON系统及路由信息协议(RIP)进行深入研究,提出一种在GPON OLT上实现RIP协议的方法,该方法实现了GPON OLT 的三层路由功能,使OLT工作在网络层,精简了宽带网络层次,增强了网络可靠性.     

基于CAM的10G EPON MAC/LLID多队列管理

基于IEEE802.3av提出了一种利用CAM IP核实现10G EPON OLT系统中MAC/LLID多队列管理的解决方案,仿真结果显示,该方案可实现协议规定的MAC/LLID多队列管理的基本功能,并提供较高的处理速度,为OLT系统的设计奠定了基础.     

Heartbeat与Drbd在大容量OLT中的应用

针对大容量OLT系统高可用性能的要求,以Heartbeat与Drbd结合为研究对象,使系统具有热备高可用的同时又具有同步文件的功能。在此讨论了Heartbeat与Drbd结合应用的基本原理及可行性,实现了其应用于大容量OLT的热备系统中,改进了切换的速度,增加其稳定性。实际测试表明Heartbeat与Drbd能很好地应用于大容理OLT中,系统快速稳定,满足应用系统高可用性。并基于开源Linux-HA项目下的免费软件使得降低成本,使其拥有更高的市场竞争力。     

基于S3C2410嵌入式系统平台的OLT网络管理的实现

根据IEEE802.3ah协议设计了一种基于S3C2410嵌入式系统平台的嵌入式EPON网络管理系统。具体阐述了此系统的软硬件平台的构建过程,中断及片选的设计,PPCBOOT的移植过程,分析了OLT与ONU通信过程中OAM帧的发现机制的状态转移图。给出了OLT远程控制管理的设计方案及具体实现。最后展望了该系统的实际前景。     

不同QoS体系结构在GPON中的实施方案

介绍了Diffserv、城域以太网和TR-156三种技术标准中对QoS体系结构的基本要求,分别讨论了该三种QoS体系结构在GPON系统上的实现方案,描述了OLT和ONT对用户数据的处理流程.在此基础上进一步分析了OLT如何通过OMCI协议中各个管理实体实现对ONT设备QoS功能的远程配置管理.     

光网OLT设备板卡资源的自动化稽核方案

光网时代,OLT设备资源管理与业务开通效率息息相关.为建立OLT设备资源的长效管理机制,实现对内提升精确管理水平、对外提升光网业务自动开通率的“双提升”目标,设计开发了OLT设备板卡自动化稽核平台.通过自动采集设备信息,比对设备侧与系统侧的资源数据,实现资源自动稽核,有效提升资源管理效率和用户业务开通满意度.     

一种延长EPON传输距离的方法

在以太无源光网络（EPON）系统中,光线路终端（OLT）和光网络单元（ONU）之间的最长光纤传输距离为20 km,但在一些较偏远地方,有些镇站距中心机房的距离往往大于20 km,提出一种延长EPON系统传输距离的方法,它在OLT上行采用光纤收发器,实现了大于20 km的EPON传输。     

EPON系统中ONU端口环路检测方案及实现

在以太网无源光网络(EPON)系统中,光网络单元(ONU)用户端口成环将会造成同一个无源光网络口下所有的业务中断。首先分析了EPON系统中ONU侧用户端口可能造成环路的主要原因及危害;然后提出了分别在OLT侧和ONU侧构造特殊报文进行环路检测的方案,并简要比较了它们的优缺点;最后对OLT侧环路检测方案的设计实现进行了重点描述。实践证明,采用OLT侧特殊报文检测方案能够有效地发现和防止ONU侧用户端口环路。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.